The present disclosure relates to a solid-state imaging device and an electronic apparatus, and in particular, to a solid-state imaging device and an electronic apparatus, capable of obtaining a better phase difference detection accuracy.
In the related art, in an electronic apparatus with an imaging function, such as a digital still camera and a digital video camera, solid-state imaging devices such as, a Charge Coupled Device (CCD) and a Complementary Metal Oxide Semiconductor (CMOS) image sensor are used. The solid-state imaging device includes pixels in each of which a photodiode (PD) performing photoelectric conversion and a plurality of transistors are combined, and an image is formed based on pixel signals which are output from a plurality of the pixels which arranged in a plane manner.
For example, in the solid-state imaging device, charges accumulated in the PD are transferred to a Floating Diffusion (FD) unit having a predetermined capacity which is provided in a connection portion between the PD and a gate electrode of an amplifying transistor. Then, signals corresponding to a level of the charges stored in the FD unit are read from the pixel and AD-converted by an Analog Digital (AD) conversion circuit having a comparator so as to output AD-converted signals.
In recent years, a technology of detecting a phase using a part of an imaging pixel of a CMOS image sensor so as to increase a speed of Autofocus (AF), a so-called image plane phase difference AF, has been widely spread. The image plane phase difference AF includes a one-sided light shielding method and a PD division method.
For example, Japanese Unexamined Patent Application Publication No. 2001-250931 discloses a solid-state imaging device adopting the image plane phase difference AF of the one-sided light shielding method, with which distance measurement is possible by covering approximately a half of the PD with a light shielding film in order for a portion of the light shielding film of a pixel to have a bias with respect to an optical center of a microlens.
Further, Japanese Unexamined Patent Application Publication No. 2000-292685 discloses a solid-state imaging device adopting the image plane phase difference AF of the PD division method, with which distance measurement is possible by dividing the PD in one pixel into two and by obtaining phase information from respective divided PDs.
For example, since the one-sided light shielding method can shield a portion on one side of the pixel by using the light shielding film or the like used in an existing wiring layer or an optical black region, it has been known that a structure can be made easily. Meanwhile, since two imaging pixels as a pair having different opening directions are desired for detecting the phase and it is difficult to obtain pixel values from the imaging pixels, it is necessary to complement pixel values from surrounding pixels.
In contrast, since the PD division method divides one PD into two, only one imaging pixel may be used and the complement of the pixel value may be achieved relatively easily.